The objective of this research project is to present the prediction model of ground motion for reasonable seismic design of structural systems on the basis of wave propagation theory and source dynamics.This project consists of two sub-projects: (I) The study on the regional factors to specify the characteristics of ground motions which would occur in Rinku town. (II)The study on prediction model of ground motion for seismic design. Sub-project(I): It has been tried to specify the active fault areas which would be important to evaluate seismic safety of a building structure in Riku town. Those areas are determined by seismic energy quantities radiated along the many faults distributed in Kinki district. Nankai trough and Chuo Kouzousen are selected as the most seismically critical and active fault areas. The soil sediment structures in Rinku town and the geolgical structure from those fault areas to bedrock have also been investigated. Sub-project(II): It has been tried to present the
… Moreprediction model of ground motion for reasonable seismic design of a building structure to be built in Riku town area. To describe the refined wave propagation path and site effect model, the soil sediment structures in Riku town area and the geological structure from fault areas to the bedrock below the ground surface have been investigated. The ground motion is theoretically modeled by the Green's function from source to site and the simple source function. The validity of the prediction model is verified through a blind prediction test for observed earthquake ground motions at Ashigra valley.1.地震動の地域的特性の要因抽出の研究:りんくうタウンに,将来到来する大きな地震動を発生させる重要な断層領域を,過去の観測地震動資料と近畿地方に分布する断層沿いの微少地震エネルギーの放出状態から,中央構造線と南海トラフであることを推定した。2.耐震設計用地震動予測モデル作成の研究:想定されたりんくうタウンの地震動特性を予測するために,りんくうタウンの建設地域で地下60〜150m近くまでのボーリング調査と,同時に軽い爆破による地盤探査を行い,りんくうタウン建設地の地盤の卓越周期,Q値,層構造等の地盤特性を把握した。また,過去の観測地震動資料から,上記の2つの断層領域からりんくうタウン建設地までの地震波の伝播性状の評価を行った。これらの資料をもとに計算されたりんくうタウンと断層領域とを結ぶ伝播経路地盤のグリーン関数と震源での破壊過程を実現する震源モデルから,りんくうタウンに建設される構造物の耐震性を予測する入力震動モデルを理論的に作成した。3.不整形地盤の地震応答の研究:半球形,円盤状の2種類の不整形地盤に点源からの波動を作用させ,不整形境界による地震動の空間的増幅・位相特性の変化および振動数依存性について調べた。 Less